gpg: Use the KEM API for ECC encryption.
* g10/ecdh.c (gnupg_ecc_6637_kdf): New. (pk_ecdh_encrypt_with_shared_point, gen_k): Remove. (pk_ecdh_generate_ephemeral_key): Remove. * g10/pkglue.c (get_data_from_sexp): Remove. (do_encrypt_ecdh): Use gcry_kem_encap of the KEM API, gnupg_ecc_6637_kdf, and AESWRAP. * g10/pkglue.h (gnupg_ecc_6637_kdf): New. (pk_ecdh_encrypt_with_shared_point): Remove. (pk_ecdh_generate_ephemeral_key, pk_ecdh_encrypt): Remove.
- GnuPG-bug-id: T7649
- Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>